Just wondering if it can hurt sportbike motors...

I'm trying a mix of 80% 91 unleaded and 20% 111 leaded in my bike right now to raise the octane up to about 95. Figured it couldn't hurt anything, since I'm pretty sure I dont have a cat to clog up.

Any thoughts?

 

what's the point? Are you running more advanced timing? Boost? Compression? Or anything to warrant needing higher octane?

 

You should just give me the money instead. I'll spend it on beer

 

you should be runningthe lowest possible octane, without pinging

 

I tried some in my bike (had some left over from my car). I don't think it helped any...maybe slowed it down. I guess it was jetted and tuned for 93 octane. Smelled good though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ngng &raquo;</TD></TR><TR><TD CLASS="quote">you should be runningthe lowest possible octane, without pinging</TD></TR></TABLE>

What he said.

My CBR 900rr needed 93 octane with out pinging. Just bought a Hayabusa and was recomended to run low octane...runs great with that.

 

Only 89 Regular in my 500R.

 

I use 89 as well. Anything higher than pump is a waste of money unless you're tuned for it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Apocalypse &raquo;</TD></TR><TR><TD CLASS="quote">I use 89 as well. Anything higher than pump is a waste of money unless you're tuned for it.</TD></TR></TABLE>

I ran 91 in my bikes; I figure that at 11,000+ rpms, why not just in case? Besides, I think I can afford the extra 30 cents per fillup.

If you run race fuel, make sure you drain it or burn most of it before riding on the street; it's a lovely odor that likes to cling to you when you are off the bike and in class/work/wherever.

 

I "have" to run 91+ (which means 93 around here) in my S4 so I need all the 30 cents I can get.

 

in run the good stuff, not gonna run a chance

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slvrblckf4i &raquo;</TD></TR><TR><TD CLASS="quote">what's the point? Are you running more advanced timing? Boost? Compression? Or anything to warrant needing higher octane?</TD></TR></TABLE>

Yes, I am running a JE bigbore pistons. They bump up the compression to 12.0:1 and increase the displacement to 1040 cc's. I am also running a D/D slip on, K & N filter and I have modified the airbox (by drilling holes in strategic locations) The bike could probably use rejetting and I was trying to compensate by raising the octane.

 

i used to have to put 91+ in my saab too untill it got totaled...

mainly because it ran 21lbs of boost out of the factory...

my bike... i use high test, but after reading this, 89 it is

 

Higher octane shouldn't hurt your motorcycle ... Only when you say race fuel I take it you are meaning leaded gas? Modern engines aren't meant for lead in them because it likes to cling to things. I can get more in depth if needed but I won't.

The higher the octane ran in a motor the better actually especially when running at higher rpms. I explained this in the thread with the person who put diesel in their bike but I will go over it again.

The octane level is a percentage of octane hyrdo-carbon chains to heptane hydro-carbon chains. These "chains" are the chemical make up of the gasoline. Octane can take compression while heptane can't. If you haven't figured out because diesel engines don't use spark plugs that means diesel gas mainly is heptane. I think roughly a 30% level of octane while regular pump gas is 87% octane. The higher octane you get the safer you are to not have your engine "knock" or misfire prematurely.

Also I am not sure but I know if there is a fuel filter of any kind lead will plug it up quickly as it after 20 gallons of leaded race fuel will clog any fuel filter to the point of clogging it where it won't flow.

So basically it doesn't hurt your engine to run higher octane as long as it isn't leaded. It also is safer to run high octanes if you are running high rpms and high compression, which I am sure most SS bikes are. Just think of it ask 30 cents more at the pump to potentially save your engine from abuse it doesn't need.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wicker Man &raquo;</TD></TR><TR><TD CLASS="quote">So basically it doesn't hurt your engine to run higher octane as long as it isn't leaded. It also is safer to run high octanes if you are running high rpms and high compression, which I am sure most SS bikes are. Just think of it ask 30 cents more at the pump to potentially save your engine from abuse it doesn't need.</TD></TR></TABLE>

I disagree. To make a higher octane out of a lower octane fuel, more catalysts must be used. These additives are not actual fuel. So, for every injector squirt, every accel pump action, every volume of air/fuel mixture, the engine is getting less actual fuel, and can exhibit lean running, poor cold driveability.

I actually experience this degradation in cold driving in my S4 on 93. I use 100 octane in my race car and that thing runs wayyyy too lean when I start it... to the point where you can't take your foot off the gas for a good 5 minutes when starting. The previous owner of my bike, who is a bike mechanic, said he's tried all grades and found 87 to run the best in my bike. He actually told me when I bought it not to let my "friends talk me into premium 'cause it's a waste" which I thought was amusing. Then again, I have a twin and Suzuki recommends 87.

Use what is specified in the manual, nothing higher. Using above that is merely a "feel-good" action by the owner. It should be noted that most manuals state the "research method" of octane, which is comparitively higher (for the same fuel) than the R+M/2 method listed on most pumps.

Moot point I know but the difference these days is more like 80 cents.

 

Actually no catalysts are needed to make gasoline into a higher octane. Actually the higher octane fuels come from the same batch as your mid ranged octane fuels.

Go to your local gas station and check out their storage tanks. I bet you there are 2 of them. They don't seperate the 89 from the 87 or the 93 from the 91. Why?

Because of the simple fact that octane is lighter than heptane. The higher octane gas will settle on the top while the lower will be on the bottom. That is why you can sort of "cheat" the system by getting gas right when the truck is there because you might get lucky and get some 89 while you are putting 87 in your car. Slim chances and it really isn't worth it. Also that is why gas stations can not go below a certain point of gas because the lower the storage is the more heptane there is then the more the cars will knock. Ever have shitty gas before and then the next day you fill it up and it is fine? Probably because the gas station you went to was low on gas.

Now when you get higher octane levels than 100 you do need additives. That is why 94 was banned because of the MTBE, methyl tertiary butyl ether, which is made from methanol and fairly cheaply but it is carcinogenic so EPA banned it and now gas is entirely additive free. Other than say if your additives are an STP gas treatment or something else. I am pretty sure Import Tuner did some research on those and octane boosters in one of their magazines. If I find it I could add some more detail about them too.

Also I feel bad for you because in NY 93 is only 18 cents more a gallon than 87.